Adjustable plug gauge



Sept. 19, 1944. A H. voLls :a1-AL.` 2,358,749

, ADJUSTABLE PLUG GAUGE y v Filed Aug. 17, 1942 35 IO 2 l 2+` *I ma() A rhhlmnhl 22 lo A H23* INVENTORS HARRY VOLIS KERR vous y ATTORNEY Patented Sept. 19, 1,944

UNITED STATES PATENT OFFICE ADJUSTABLE PLUG GAUGE Harry Volis and Kerr Volis, Detroit, Mich. Application August 17, 1942, Serial No. 455,056 1 claim. .(01. 33-178) The present invention relates to gauges for making accurate measurement o-f the dimensions of openings of cylindrical or other shape, though more especially designed for use with bored or drilled holes.

Among the objects of the invention is a plug gauge having a micrometer adjustment.

Another object is a gauge of the kind indicated which will have a wider range of adjustment than those heretofore known.

Other objects will readily occur to those skilled in the art upon reference to the following description and the accompanying l drawingV in which Y Figure 1 is a view in elevation of a gauge embodying the invention.

Figure 2 is a central longitudinal section thereof.

Figure 3 is an end view of the gauge with parts extended; and

Figure 4 is a section on line 4-4 of Figure l.

In the drawing, the gauge is indicated as comprising an accurately cylindrical body I8 having four diametrical holes therethrough, `two of which are parallel while the other two are likewise parallel but intersect the first two at right angles, thus providing eight radially arranged passages. l

One end of the cylindrical body IIJ is provided with a concentric extension II and both the eX- tension and body are bored axially, as at I2, the bore being counterbored as at I3 and threaded vfor a short distance as indicated at I4.

noted. Further, the cap 22 preferably is of such i size that its skirt 23 overlies the end of the statio-nary body extension I I which likewise carries graduations,v indicated at 23a. These two sets of graduations 23` and 23a are preferably convenf tional. g

Further, in order to limit the longitudinal movement of shaft 20 it is provided with a peripheral channel 24 in which lies a transverse pin 25, the ends of which as well as the greater part of body extension II being covered by an outer sleeve 26. i y

Accurately iitted in the diametrical holes in body I8 are eight preferably identical pins 38, bevelled at their inner ends at diametrically opposite points as at 3l to permit suicient inward movement to allow one set of the pins to contact the part I6a of shaft I5 and the other set a like movement.

In addition to the bevelling mentioned, each pin 30 is bevelled or provided with a sloping surface 32 having the same angularity as the cones I 6 and arranged to coact therewith to cause outward radial movement of the'pins when the shaft 20 is rotated in the threads I4 to move it, and thereby shaft I5, toward the body I8.

In order to provide for the inward movement of pins 30 when the shaft 28 is retracted, each pin is flattened on one side for the greater portion of its length as indicated at 35, leaving a shoulder 36 against which acts a Spring `3'I, abutting at its other end againstra plate or retainer strip 38, which also, lying against vthe vflat sides ofpins 38, prevents the pins from rotating.

It is, of course, to be understood that the outer ends of the pins 38, the plates 38 and bodyA I0, are

ing similar angles of slope and spaced apart a distance equal to the space between the parallel diametrical holes above mentioned.

The rear end of shaft I5 is provided with a seat I'l for a steel ball I8 serving as an antifriction bearing between shaft I5 and the end of shaft 20.

This shaft 20 is threaded, as at 2|, intermediate its ends, to cooperate with the threaded portion I4 of body extension II, so that rotation moves the shaft 20 longitudinally and, when the shaft is in contact with ball I8, likewise moves longitudinally the shaft I5.

'I'he outer end of shaft 20 is preferably xed in a knurled cap 22 carrying graduations 23 by accurately finished to present a smooth cylindrical surface when the pins are fully retracted.

Now having described the preferred form of embodiment of the invention, what is claimed is:

In an adjustable plug gauge, a radially movable plug having one side cut away for a portion of its length whereby to present a flat lateral surface and likewise .a shoulder, a plate xed against said flat side of said plug and thereby preventing plug rotation and a spring under compression arranged between said plate and said shoulder. f

HARRY VOLIS. KERR VOLIS. 

